While the invention is subject to a wide range of applications, it is especially suited for use in a valve system and will be particularly described in that connection.
In metering minute amounts of gas from a high pressure to a low pressure area, very precise valve devices are required. The valve must be capable of accurately controlling the entrance of minute quantities of gas in to a vacuum where a quantity of gas admitted may be a fraction of a cc or even smaller amounts approaching molecular quantities. This can be especially difficult where the inlet port is of a much higher pressure than the outlet port as where the gas at atmospheric pressure is introduced into a vacuum.
In the past, this has been accomplished by a precision metering valve of the type disclosed in U.S. Pat. No. 3,139,262 to Morris et al, which discloses for example "micrometer means for manually controlling the rate of flow through a valve body with high rate of precision". Also, a precision metering valve similar to the type disclosed in the present invention has been made and sold in this country. However, a problem has existed in that substantial torque is required to adjust the valve. Thus, the precision control provided by a micrometer on the valve is relatively difficult to precisely adjust.
It is an object of the present invention to provide a metering valve which can precisely meter a gas flow.
It is a further object of the present invention to adjust.